The invention relates to a fuel filter, in particular for internal combustion engines of motor vehicles. The fuel filter comprises a filter housing, a filter element, and a riser tube. The filter element is arranged in the filter housing such that in a bottom area between the filter element and the filter housing a water collecting chamber is formed. The filter element has an annular structure and comprises a coalescing element and a particle filter element, wherein flow passes through the coalescing element from the interior to the exterior and flow passes through the particle filter element from the exterior to the interior. A raw (unfiltered fluid) chamber is formed within the coalescing element and a clean (filtered fluid) chamber is formed within the particle filter element. The riser tube extends through the raw chamber and the clean chamber. The riser tube, on the one hand, forms a clean channel and, on the hand, a guide channel wherein the riser tube has sealing means for sealing the clean chamber and the raw chamber relative to one another.
U.S. Pat. No. 5,788,859 discloses a fuel filter that is screwed onto a filter top. The fuel filter has a housing comprised of a housing cup as well as a housing lid. The filter is configured as an exchangeable filter cartridge that cannot be opened. In the housing cup a single-stage filter element is provided that separates seal-tightly a raw side from a clean side. The raw side communicates with fuel inlets that are arranged in the housing lid. The fuel outlet that is also arranged in the housing lid is communicated with clean side. The clean side is enclosed by a filter element that is of a cylindrical hollow configuration. The raw side is formed between the housing cup and the filter element. When filtering the fuel, water that is contained in the fuel is prevented by the filter medium from reaching the clean side. Because water has a higher density than fuel, the water collects in the bottom area of the housing cup. The bottom area of the housing cup is connected by means of a riser tube to the filter top. In this way, the riser tube extends through the clean side wherein between the filter element and the riser tube seals are provided. All components are fixedly connected to one another so that an exchange of the filter medium requires the disposal of the entire fuel filter.